hi, I'm finishing up my lockdown project... and the fiesta xflow thermostat housing I've got fitted has stopped letting water through into my expansion tank.
I've got my rad covered with a 12lb cap, I've removed the thermostat from the housing (just in case it was that) and I've got a blank on top of my expansion tank. I reckon the system is now unpressurised (if that's the word), but when I run it up to temp the 12lb cap on the rad lets water passed before the expansion tank gets warm. This carries on until the engine fan cuts in. Any ideas please? I can post pics if that helps. Cheers

Hi,
Usually there is a small hole in the stat to allow some water to pass through, but if the stat is removed it should warm up slower as the water should be restricted to allow it to get hot quicker. It could be that your water pump isn't circulating the water and therefore the water isn't being pumped up to your expansion tank. It could also be that your tank isn't in the main circuit so being missed by the water flow, although that would be odd.
Try and draw up your water circuit for us all to see so that we may be able to spot any obvious answers for you

Jason
ps, on my locost, i have the outlet from the inlet part of the head blocked off, so the inlet to the header tank is directly off the take off point on the water pump, the return is to the thermostat housing point, this warms up fairly quickly and is off choke well before the fan kicks in even when running in the garage.

cheers. trying to insert an image...

[img]https://photos.google.com/photo/AF1QipM9oIOkh6STIqFavsXyIlLAezqX8zaYud_OY1i6[/img]

[Edited on 12/9/20 by timB]

[Edited on 12/9/20 by timB]

In my head, the water expands up the black tube from the thermostat housing and raises the level in the expansion tank on the right. Electrically, it would be a spur
thanks

[Edited on 12/9/20 by timB]

Hi ya,

Mine gets a small trickle of water generally going through it, and pressurises well when the stat opens and allows the better flow around the system. Also if I squeeze either rad feed pipe, the water level in the tank goes up as expected, have you tried that on yours ?

Jason

Check the bleed off pipe , the hose and the connection to the header aren’t blocked. Do you have the hose from the inlet manifold to the heater/ water pump connection in place? Without the hose in place air is trapped . I fitted a bleed point in the heater hose at the highest point on my car which helped when filling and bleeding the cooling system

Bingo. Bleed off pipe (to expansion tank) was blocked. I'm going to need to flush out out because there was a fair amount of crystals in the thermostat housing.

Thanks for the help everyone.